How to measure corrosion in pumps

Corrosion in pumps is a serious concern in pumping systems. This is because lack of proper pump monitoring could lead to catastrophic failure of a pump.That being said, the selection of the proper material for the pump is extremely important in addressing this concern.

Moreover, the material selection is dependent on other factors such as the fluid being pumped or speed of rotation of the pump.

Failure to select the correct material for an application has been proven to accelerate the effects of corrosion. Similarly, choosing the best-suited material for an application will dramatically reduce the effects of corrosion.

To avoid and or prevent the dangers of corrosion in pumps altogether, it is advisable to keep in constant check the pumps applied in systems where corrosion is a known risk. This will help ensure normal operation. On the other hand, there are several methods for corrosion monitoring that have been proven to work.

For instance, visual inspection of the pump is the easiest and can reveal corrosion damage occurring in the pump. This, however, comes with a major drawback as it requires the pump to be shut off and taken apart. Additionally, stress cracking could have no visible signs in the visual check, but later cause sudden distress that will prove to be catastrophic to the pumping system.

On the other hand, general corrosion can be detected through the use of a metal probe to measure the electrical resistance. This works such that when the cross section is reduced by corrosion, the measured electrical resistance will increase.

Metal probes can also be used to measure the linear polarization resistance. A voltage is applied using the probes, and the resulting current is proportional to corrosion rate. Finally, ultrasonic thickness measurement can be used to determine the thickness of an area on the pump. This will then indicate if thickness is being lost due to corrosion.